This invention relates to torsional sleeve couplings. More particularly, the invention relates to a novel spring dampening system for absorbing torsional vibrations generated in a driveline assembly.
There are a number of prior art systems designed and adapted for absorbing driveline vibrations of the type common in vehicular applications. A major source of such vibration exists between the pinion shaft gears and the ring gear of a differential within the driveline assembly during non-driving, low torque range modes of operation. Thus, for example in an "all-wheel" drive vehicle being driven selectively only by the front wheels, the rear wheels will "coast", and the differential pinion shaft will be back-driven by the differential ring gear. During such back-driven rotation of the pinion gear, the differential ring gear teeth will typically chatter against the pinion gear teeth, resulting in transmission of vibration throughout the driveline assembly components. Several prior art systems designed to accommodate this non-driving mode phenomenon provide workable, but unsatisfactory solutions. Most of the existing systems are cumbersome to manufacture, expensive to fabricate and install, and/or have severe operating limitations.
For example, several designs utilize a torsional coupling sleeve with rubber to provide a dampening effect. To the extent that the spring rate of rubber is highly temperature sensitive, the latter systems are relatively useless in extremely cold weather.
What is needed is an inexpensive, easily fabricated, simple to install torsional sleeve coupling system which will provide a satisfactory torsionally dampened performance of a driveline coupling during the non-driving mode of the driveline under virtually all practical limits of operation.